首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2121篇
  免费   219篇
  国内免费   13篇
耳鼻咽喉   20篇
儿科学   81篇
妇产科学   34篇
基础医学   372篇
口腔科学   34篇
临床医学   235篇
内科学   534篇
皮肤病学   51篇
神经病学   115篇
特种医学   119篇
外科学   226篇
综合类   39篇
一般理论   4篇
预防医学   179篇
眼科学   19篇
药学   179篇
肿瘤学   112篇
  2023年   11篇
  2022年   12篇
  2021年   32篇
  2020年   29篇
  2019年   30篇
  2018年   34篇
  2017年   35篇
  2016年   46篇
  2015年   44篇
  2014年   54篇
  2013年   79篇
  2012年   123篇
  2011年   95篇
  2010年   60篇
  2009年   56篇
  2008年   86篇
  2007年   100篇
  2006年   82篇
  2005年   106篇
  2004年   94篇
  2003年   101篇
  2002年   81篇
  2001年   60篇
  2000年   66篇
  1999年   57篇
  1998年   43篇
  1997年   32篇
  1996年   30篇
  1995年   25篇
  1994年   32篇
  1993年   29篇
  1992年   58篇
  1991年   45篇
  1990年   44篇
  1989年   43篇
  1988年   43篇
  1987年   49篇
  1986年   40篇
  1985年   37篇
  1984年   26篇
  1983年   14篇
  1982年   13篇
  1981年   10篇
  1980年   15篇
  1979年   14篇
  1978年   14篇
  1977年   13篇
  1976年   13篇
  1972年   11篇
  1968年   9篇
排序方式: 共有2353条查询结果,搜索用时 15 毫秒
101.
Larva therapy in wound management   总被引:12,自引:0,他引:12       下载免费PDF全文
The use of maggots for wound debridement has a long history and has lately gained ground in several countries. We collected prospective data to examine the current use of larva therapy (LT) in the UK. Quantitative information was collected on 70 patients treated in nine hospitals. LT is used primarily to treat leg ulcers and generally involves three applications of larvae at two to three day intervals. This method is judged effective in wound debridement and promotes the growth of granulation tissue. Wound exudate, odour, infection and pain are all reduced by the treatment. Adverse reactions are infrequent but include pain, bleeding, pyrexia and influenza-like symptoms. Prevention of hospital admission and surgery, reduced need for antibiotics and reduced hospital stay are all identified as outcomes of LT. The nurse practitioners who used LT believed it to have an important role in wound management. A randomized clinical trial, comparing LT with other debriding agents, is required for evaluation of cost effectiveness.  相似文献   
102.
We have recently demonstrated that intramuscular administration of triiodothyronine (T3) or thyroxine (T4) to the rabbit doe results in its transfer across the placenta. In this study we investigated the effect of maternally administered T3 upon the functional and morphologic fetal lung maturation. T3 (175 micrograms/kg) or the vehicle was injected intramuscularly into the New Zealand White rabbit does on days 25 and 26 of gestation. On day 27 of pregnancy, the does were killed and the fetuses were delivered. Maternal and fetal plasma T3, glucose and insulin and fetal plasma corticosteroid concentrations were determined. The functional pulmonary maturity was assessed by performing the pressure-volume hysteresis while morphologic maturity was established by histologic techniques. Enhanced functional as well as morphologic fetal lung maturation was observed in female as well as male fetuses in T3-treated animals. However, there was a significant increase in the fetal mortality after T3 treatment, and the duration of survival in the extrauterine environment on premature delivery was not prolonged.  相似文献   
103.
Severe combined immunodeficiency is one of the most common causes of primary immunodeficiencies in humans. Molecular biological techniques have allowed new, therapeutically useful treatments for these diseases to be introduced into clinical practice. This review will focus on the molecular basis and new treatments for X-linked severe combined immunodeficiency.  相似文献   
104.
Objective: There is evidence that individuals high in hypochondriasis overestimate the likelihood of ambiguous symptoms being indicative of serious illness. However, it is not known whether this tendency is unique to hypochondriasis or whether it can be attributed to high negative affectivity or other anxiety symptoms often found to be comorbid with hypochondriasis. Method: College students (N=133) completed measures of hypochondriasis, depression, anxiety, worry, avoidance and estimated the likelihood of various symptoms indicating catastrophic and minor illnesses. Results: Even after entering the other self-report variables, hypochondriasis was the only variable to predict estimates of the likelihood of serious illness. Conversely, being female, high levels of negative affect, agoraphobic avoidance when accompanied by others and higher estimates about the likelihood of symptoms leading to catastrophic illnesses best predicted hypochondriasis scores. Conclusion: Dysfunctional beliefs about illness appear to be unique to hypochondriasis and to uniquely contribute to the prediction of hypochondriasis.  相似文献   
105.
106.
107.
108.
Antithrombin (ATIII), heparin cofactor II (HCII) and protein C inhibitor (PCI; also named plasminogen activator inhibitor-3) are serine protease inhibitors (serpins) whose thrombin inhibition activity is accelerated in the presence of glycosaminoglycans. We compared the inhibition properties of PCI and HCII to ATIII using R93A/R97A/R101A thrombin, an anion-binding exosite-2 (exosite-2) mutant that has greatly reduced heparin-binding properties. Heparin-enhanced PCI inhibition of R93A/R97A/R101A thrombin was only approximately 2-fold compared to 40-fold enhancement with wild-type recombinant thrombin. Thrombomodulin (TM) (with or without the chondroitin sulfate moiety) accelerated PCI inhibition of both wild-type and R93A/R97A/R101A thrombins. HCII achieved the same maximum activity in the presence of heparin with both wild-type and R93A/R97A/R101A thrombins; however, the optimum heparin concentration was 20 times greater than the reaction with wild-type thrombin, indicative of a decrease in heparin affinity. Dermatan sulfate (DSO4)-catalyzed HCII thrombin inhibition was unchanged in R93A/R97A/R101A thrombin compared to wild-type recombinant thrombin. These results suggest that PCI is similar to ATIII and depends upon ternary complex formation with heparin and these specific thrombin exosite-2 residues to accelerate thrombin inhibition. In contrast, HCII does not require Arg(93), Arg(97) and Arg(101) of thrombin exosite-2 and further supports the hypothesis that HCII uses an allosteric process following glycosaminoglycan binding to inhibit thrombin.  相似文献   
109.
The debate as to whether schizophrenia is a neurodevelopmental or a neurodegenerative disorder has its roots in the latter part of the 19th century when authorities such as Clouston (1891) posited that at least some insanities were "developmental" in origin. These views were soon eclipsed by Kraepelin's (1896) concept of dementia praecox as a degenerative disease, and the latter view carried not only the day but also much of the 20th century. Then, in the 1980s several research groups again began to speculate that schizophrenia might have a significant developmental component (Feinberg, 1982-1983; Schulsinger et al., 1984; Murray et al., 1985; Murray and Lewis, 1987; Weinberger et al., 1987). What became known as the "neurodevelopmental hypothesis" received support from neuropathological studies implicating anomalies in early brain development such as aberrant migration of neurons. Unfortunately, these studies proved difficult, if not impossible, to replicate (Harrison, 1999). The pendulum, therefore, began to swing again, and in the latter part of the 1990s came renewed claims that the clinical progression of the illness was accompanied by continued cerebral ventricular enlargement and reduction in the volumes of certain brain structures. Nevertheless, since few doubt that there is a developmental component to schizophrenia, the question which we will address in this paper is whether schizophrenia is a) simply the final consequence of a cascade of increasing developmental deviance (Bramon et al., 2001), or b) whether there is an additional brain degeneration following onset of psychosis which is superimposed on the developmental impairment (Lieberman, 1999).  相似文献   
110.
Church EJ 《Radiologic technology》2002,73(6):537-64; quiz 569-72, 567
Medical imaging plays a key role in many aspects of organ donation, procurement and transplantation. Imaging techniques are used to confirm a diagnosis of brain death, measure organs, assess potential donors and recipients, and evaluate the success of surgery. This article offers an overview of organ donation and transplantation. After completing this article, readers will: Understand what U.S. laws apply to organ donation and which organizations play a part in the transplant process. Describe methods for determining death. Explain how organs are procured and allocated. Describe the role medical imaging plays in organ donation and transplantation. Discuss the controversies surrounding organ donation.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号